The event organisers and Billabong both said the World Surf League determined the prize money and they were committed to gender equality.

“The Ballito Pro maintains its stance as a pro-gender equality competition, which is evident from the ongoing development of the women’s series year-on-year,” the organisers said. “Based on this commitment to equality, we are meeting with all relevant stakeholders to discuss how any potential discrepancies can be resolved.

“The World Surf League is the sanctioning body for WSL-aligned surfing events such as the Ballito Pro. The WSL implements certain criteria to determine surf ratings and prize money, and we have formally requested a detailed outline of this process for future discussion.”

Will Hayden-Smith, WSL’s regional manager, told the ABC in Australia that the photo of the winners “on first glance does look like a huge disparity”.

The issue at stake is the size of the prize-money pot per surfer. Since the WSL came into existence in 2014, prize money for men and women has been at parity, but the men’s pot is bigger because the male field is almost double the size. The idea is that the average take-home per surfer, male or female, from each event is roughly the same.

Surfing South Africa’s general manager, Robin De Kock, told Cape Town radio it would fight against any unfair pay practices and that it was unusual for men and women to be paid differently at the amateur level.

“Women and men pay the same entry fee, so they should get the same prize money,” De Kock said. “We are not going to let this rest. It is an embarrassment to surfing.”